Oil composition for saturating cable wrappings



. trolatum or grease of suitable consis-' Patented Aug. 3, 1926.

ALBERT A. SOKERVILLE, OF FLUSHING, NEW YORK, ASSIGNOR 0]! 'IWO-THIRDS TOB. '1. VANDERBILT COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORA-TION OI NEW YORK.

OIL COMPOSITION FOR SATUBA'IING CABLE WRAIPIN No Drawing.

This invention relates to an improved oil or grease composition for usein saturating the paper or other materials used as-a wrapper forelectrical cables.

In the manufacture of cables for use as conductors of electricalcurrent, the wrap ping of paper or other material is saturated with asuitable oil composition, such as petency by passing the wrapped cablethrough a hot saturating or impregnating bath of the oil composition.The oil or grease is, in general, such as is not fluid below 30 C. andhas a viscosity of not less than 100 seconds at 100 C. as measured bythe Saybolt viscosimeter. In the manufacture of continuous lengths ofcable, the impregnating bath is maintained at high temperature for longperiods of time. The result, however, is that the saturating bathrapidly deteriorates in its insulating properties, and, at more or lessfrequent intervals of time, it is necessary to remove the bath andreplace it with a fresh bath of suitable insulating properties.Moreover, after the impregnating bath is used, and after the wrappedand. saturated cable is enclosed in the usual lead casing, thesaturating composition undergoes further deterioration under theinfluence of electrical stress and of the elevated temperatures to whichit may be subjected in use.

The present invention provides an improved saturating or impregnatingcompo-- sition which can be used for greatly prolonged periods of time,as compared with the ordinary saturating or impregnatingcomposition,-and which is stabilized so that it will resistdeterioration, both during the saturating or impregnating operation, andduring the subsequent use of the finished cable as an electricalconductor.

According to the present invention, the petrolatum or greasecomposition, which is to be used for saturating the wrappings of cables,has compounded therewith a small .amount of a nitrogenous stabilizingagent which will retard orprevent deterioration, both during thesaturating treatment and during the subsequent use of the cable as anelectrical conductor. When the cable wrapping is saturated with such astabilized composition, the resulting cable may be considered .as asubstantially. permanent con- Application filed January 8, 1926. SerialNo. 80,065.

struction with a .minimum'liability of deterioration of the saturatingor impregnatmg oil composition with which the wrapping is saturated.

The stabilizing materials which are added, in small amounts, to the oilcomposition used for saturating the wrappings of cables, may be of asomewhat varied character. Of particular advantage are compounds withinthe "group of organic amines, or imines, and particularly condensationproducts of aldehydes with ammonia or with amines. In general, thecompound so added should be non-volatile at the temperature at which thesaturating compositlon is used, and it should also be stable in thesense that it: is not decomposed into volatile or objectionablecompounds at such temperature 'of use. The material added should also besoluble in the oil or grease composition to such an extent that it Willform a homogeneous admixture therewith. An oil of the general class ofpetroleum oils and containing a stabilizer comprising specifically thecondensation product of an aldehyde and a nitrogenous base is claimed inmy copending application Serial No. 103,- 374, filed Apr. 20th, 1926.

The stabilizing ingredients or ingredient may be added directly tothe-oil, if readily soluble therein, or the dissolving of thestabilizing material may be promoted by heating, or the material may befirst dissolved in a solvent such as-benzol, and the benzolmonly usedfor impregnating the paper wrapping of cables, has added thereto a smallamount. e. g. 0.5% to 1% of a condensation product of acetaldehyde withanilin, the admixture being promoted by dissolving the condensationproduct in benzol and then intimately admixing the benzol solution withthe saturating bath. When the resulting composition is used for saturatng the paper wrapping of cables, by passing the cable through the hotsaturating bath,

the bath .will retain high insulating proper ties for long periods oftime. In fact, the bath mav increase in its electrical resistivity fromthat of the original oil being in this respect. radically different fromthe ordinary saturating bath which rap1dl v deteriorates in itselectricalresistivity. Not only is 1t possible to use the saturatingbath for greatly prolonged periods of time, but the resulting cableswhich have the wrappings satu rated with the improved stabilizedcompos1- tion, will likewise. resist deterioration 1n use, thus being amore valuable and 1mproved form of cable construction.

The mineral oil composition used for uppregnating cable wrappings mayhave I'OSlIl oil or pine oil added thereto, to impart somewhatdifi'erentcharacteristics to it, such as a change in viscosity and flow point.When such oils are added, the nitrogenous stabilizing ingredient oringredients may be added to a mineral oil or with a pine oil or rosinoil. 7

Instead of using a condensation product of acetaldehyde and anilin, thecondensation product of aldol and alphanaphthylamine can be similarlypod.

While I do not wish to limit myself by any theoretical explanations ofthe action of the stabilizers used in the present invention, yet Ibelieve their actions to be due to prevention of oxidation at theelevated temperatures to which the oils are subjected in use. Althoughthe stabilizing ingredients are used only in very small amounts,

not usually exceeding about 2%, and in some cases being only a fractionof a per cent. nevertheless they appear to impart remarkable stabilityto the oil compositions from the standpoint of preventing the usualrapid deterioration of such oil compositions at elevated temperatures.

Instead of using the particular stabilizing materials above mentioned,other nitrogenous stabilizing materials can be used. Among these may bementioned other members of the group of organic amines and imines, suchas homologues of anilin, benzidin and its homologues,paraphenylenediam-inc, and other aromatic diammes, alpha or betanaphthylamine, etc. Among the condensation products of aldehydes andammonia or amines may be mentioned, in addition to those above given,other condensaacetaldehyde with anilin (both the acid and i the neutralcondensate), the condensation product of formaldehyde with anilin, thecondensation product of acetaldehyde with ortho or para toluidine, etc.,the condensation product of furfuraldehyde with am-' monia or withaniline or orthotoluidine, etc.

It will thus be seen that the present invention is of more or lessgeneral application to petroleum oil compositions of the kind used forsaturating cable wrappers imparting to these oils improved stabilizedproperties such that they resist the usual deterioration and can be usedfor long periods of time without losing their valuable electricalinsulating properties. It will also be seen that-,in the case of thecables which have their wrappings saturated with the new composition,the resulting cables are themselves of an improved character, because ofthe stabilized nature of the saturating composition with which the cablewrappings are saturated.

'I claim v 1. An improved composition for saturating cable wrappings,comprising petrolatum and a small amount of a nitrogenous stabilizingmaterial which retards loss of electrical resistivity of 'the saturatingmaterial-at an elevated temperature during the saturating of the cablew-rappings, and subsequently in the use of the cables as electricaloonductors.

2. An improved composition for saturat-f ing cable wrappings, consistingof a petroleum oil of suitable consistency and a small amount of aninert nitrogenous stabilizing material substantially free from acidradicals which retards loss of electrical resistivity of the saturatingmaterial at an elevated temperature during the saturating of the cablewrappings, and subsequently in the use of the cables as electricalconductors.

3. In a process for treating cable wrappings, the step of impregnatingthe cable wrapping with a composition comprising a petroleum oil ofsuitable consistency and a condensation product of a nitrogenous baseand a carbonyl compound.

- In testimony whereof I afiix my signa ture.

ALBERT A. SOMERVILLE.

